The present invention relates to a process for preparing an oleogel.
Structure in solid fat-containing food products is provided by the network of crystalline triacylglycerols. However, these triacylglycerols contain high levels of saturated fatty acids. Instead of using naturally highly saturated solid fats, oils comprising triacylglycerols having high levels of unsaturated fatty acids are also transformed to more solid products by hydrogenation or partial hydrogenation. “Trans fats”, which are unsaturated fats with trans-isomer, unavoidably emerge from partial hydrogenation of unsaturated oils. Research into the role fats and oils play in human health has indicated that consumption of saturated fatty acids, especially trans fatty acids, is associated with elevated cholesterol levels and cardiovascular diseases.
Therefore, it would be desirable to develop healthier alternatives to triacylglycerols containing saturated or partially hydrogenated fatty acids. The demand for a healthy alternative to trans fats and saturated fats creates technological hurdles for the food manufacturing industry. It is difficult to eliminate trans and saturated fats from a food formulation where the goal is to transform a healthier unsaturated oil, which is liquid at room temperature, to a fat, which is ‘solid’ at room temperature, in order to enhance the texture and appearance of a food product.
In the food industry there have been many attempts to find alternative components that can provide the desired features of texture, structuring, stability and taste that are normally found in animal and vegetable fats or hydrogenated oils. One alternative, organogels (oleogels), have been recognized for their potential to be used to reduce oil migration in multicomponent foods and to act as an alternative to butter or margarine. Oleogels can be used to provide structure to edible oils thereby reducing the need for saturated and trans fatty acids.
An ethylcellulose oleogel may also be useful as an ingredient to a cosmetic composition to render a film left by the composition more hydrophobic and resistant to rub off. An ethylcellulose oleogel may also be the carrier phase of a cosmetic or cosmeceutical product. The ethylcellulose oleogel could also be used to deliver an active in a cosmetic or cosmeceutical product.
U.S. Pat. No. 6,187,323 describes the preparation under non-shear conditions of pharmaceutical and cosmetic compositions comprising a mixture of an oleogel and an aqueous gel. In the example, a semisynthetic triglyceride is gelled with ethylcellulose in the presence of propylene glycol isostearate by stirring the components at 140° C. until a uniform oleogel is formed.
In “Influence of the Concentration of a Gelling Agent and the Types of Surfactant on the Rheological Characteristics of Oleogel” (Il farmaco 58 (2003) 1289-1294) M. A. RuíMartínez et al. report on oleogels comprising olive oil, ethylcellulose and a surfactant selected from Olivem 300, 700 and 900. The oleogels were prepared by adding ethylcellulose and a surfactant to the oil phase, then stirring the components while heating to 100° C.
U.S. Pat. No. 4,098,913 describes edible fat particles for incorporation into textured protein meat analog products. The edible fat products are made by gelling a triacylglyceride fat or oil with ethylcellulose. In the example, partially hydrogenated cottonseed oil is mixed under rapid stirring with ethylcellulose at 180° C.
WO 2010/143066 relates to an edible oleogel comprising an oil, ethylcellulose and a surfactant. The oleogel is obtained by heating the ethylcellulose and the surfactant in oil to a temperature (Tg) above the glass transition temperature of the ethylcellulose with constant mixing. Suitably, the mixture is heated up to at least 130° C. to about 160° C. and after a few minutes a clear and very viscous solution is formed.
The problem underlying the present invention is to provide a new process of preparing a solid or semi-solid fat product, such as an oleogel.